A conventional geodesic lens antenna (GLA) can provide an antenna solution for low cost, and weight restricted applications. A typical geodesic lens antenna has many advantages, including simplicity of design. Due to its ease of construction and design, geodesic apertures are suited for applications that require 360° coverage in azimuth. For certain applications it is desired to perform simultaneous azimuth and elevation beam pointing, while still using a simple, low part count, geodesic lens approach.
One drawback of known GLAs is the inability to form antenna beams in two simultaneous dimensions (namely, azimuth and elevation). One conventional approach to solving this shortcoming is to adding azimuthal slots in the vertical dimension. For example, the geodesic slotted cylindrical antenna of Howell, et al., U.S. Pat. No. 6,011,520, (incorporated herein by reference in its entirety) incorporates horizontal radiating slots in the geodesic lens cone to create an elevation illumination profile for elevation beam shaping. This approach does not provide for elevation beam steering by purely electrical means, however. Furthermore, the time of arrival to the horizontal slots varies with frequency and is limited to narrow band operations due to elevation “beam walk” (or “beam wander”) caused by the frequency sensitivity of the horizontal slot approach.
Another attempt to solve this and other related problems may be seen in the geodesic cone antenna of B. S. Cramer, “Geodesic Cone Antenna,” Proceedings of the Antenna Applications Symposium (ADA142003), vol. 1, March 1984, incorporated herein by reference in its entirety. However, the proposed design is not capable of elevation steering.
Similarly, another antenna design is discussed in Wyman Williams and Chris Burton, “Lightweight agile beam antennas for UAVs,” Proceedings of the 2006 IEEE Conference on Military Communications (MILCOM '06), IEEE Press, Piscataway, N.J., USA, pp. 115-119, incorporated herein by reference in its entirety. This design is also not capable of elevation steering, but does allow a certain amount of beamforming.
What is needed is a relatively simple, yet compact, geodesic lens antenna system that is able to provide full electronic azimuth and elevation beam steering.